Method for producing wells and strainer shoe for the same



July 17,- 1928.

T. W. THORPE ET AL METHOD FOR PRODUCING WELLS AND STRAINER SHOE FOR THE SAME Filed Jan 20, 1926 f fg/MW wir Patented July 17, 1928.

UNITED sTATEs PATENT oFFicE.

THOMAS w. 'riionrE AND GEORGE E. THOEPE, 0E nEs MOINES, IOWA;

IMETHOD FOR LPRODUCI'NG WELLS AND STRAINER SHOE FOR THE Application filed January 20, 1926. Serial No. 82,446.

The object of our invention is to provide outer casing may a proper depth may be placed below outer casing so that continuation of the the straineris inserted in t formation, practically to the lowering or insertin within such formation.

It may be here mention for wells are ordinarily inserted in the well casing or well casthrough the watervbearing forniaby first driving the outer ing down be inserted in the ground and thereafter a` strainer the lower end of the the strainer serves as a outer casing and when he water bearing no resistance is had g of the strainer ed that strainers tion and thereafter lowering the strainer into the casing and then drawing the outer casing er exposed within tion anduthis practice finds raising or withleaving the strainthe water bearing formamany difficulties,

one of which is the almost impossibility of withdrawing the outer casing through cement, gravel and sand formations which are ordinarily found just abovefthe water bearing formation.

In driving an outer casing throughy so called glacial drifts we find that the outer casing may be driven dow when 1t is necessary nwaidly and yet to elevate the casing so that the strainer is exposed, we find that the glacial substance. binds against th drifts which is a claj)7 or sand e outer casing so that the outer casing can not be raised and in many cases the casing becomes broken by the upward pull and in such a case the work already done is practically It is our object to overcome worthless.

the difficulties and disadvantages of having to remove part of the outer casing or raise pose thcstrainer.

these difliculties we employ it in order to ex- Iii order to overcome a shoe which carries a strainer and the shoe and strainer are inserted within thc casing and permitted to 'go to the lower end thereof, at which time the gravel of the water bearing formation is removed and the weight of the strainer and the shoe will tend to work themselves downwardly through the water bearing formation and thus the strainer isexposed below the lower end of the outer casing and forms ractically a continuation thereof. K

Still a further object is to produce a well which comprises the inserti ng in the ground o f an outer casing until it reaches the desired depth which is ordinarily when its lower end rests upon the upper surface of the water bearing formation and thereafter inserting a. second casing within the outer casing having a shoe'oii itsl lower end and driving the second casing and shoe through the water bearing formation. the shoe being of a greater diameter than the second or inner casing and of less diameter than the outer casing, wherein a strainer may be carried by theshoe and inserted between-the outer casing and innerscasing during the time it is lowered.l

The strainer is of no greater diameter than the shoe itself and will follow the shoe downwardly below the -lower end of the outer casing wherein the strainer practically forms a continuation ofthe casing itself and upon removal of the inner casing, water may be draw-n through the strainer and into the outer casing.

Still a further object is to ,provide a shoe .for carrying a strainer through water bearing formations which shoe consists of an open ended tubular member having its lower end sharpened so as toeasily pass through the water bearing formation 'and having a shoulder formed above its lower end upon which rests the strainer.

The outer diametei' of the shoe and strainer being substaiically no resistance or pressure against the strainer itself.

Still a further object is to provide the shoe with a shoulder on its inner surface against which an inner casing may rest where the shoe may be forced down through the water bearing formation and the gravel of the water bearing formation withdrawn through the shoe and through the casing in communication with the'shoe.

lVith these and other objects in view, our invention consists -in the construction, arrangement and combination of the various parts of our'invention, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Figure 1, is a perspective view of our imlos f sink an proved shoe, parts beingshown in section to better illustrate the construction thereof.

Figure 2, is a sectional view showing the lower end of an outer well casing-and ythe water bearing formation below the lower end of the casing and the strainer about to be inserted in position.

Figure 3, is a similar sectional view shows ing the strainer in installed position within the water bearing formation and the lower end thereof sealed and `Figure 4, is a sectional view through the strainer shoe with a concrete strainer resting thereon. -4

In the accompanying drawings we have used the reference character A to indicate generally a\ metal shoe which is tubular throughout its length and has both of its ends open.

The lower end of the shoe` A is pointed or sharpened as at 10 so as to easily pass through water bearing formation whichwe will hereinafter more lfully explain.

The shoe A includes a shoulder 11 upon which may rest a strainer 12. The strainer 12 rests upon the shoulder 11 and is supported by a portion of the shoe itself which extends up into the strainer 12.

The strainer may be secured lto the shoel A in any suitable manner. It will be noted that the diameter of the strainer 12 is practically the same as the overall or greatest diameter of the shoe A and this is of importance when lowering the strainer and shoe in through the water bearing formation.

The shoe A is formed on its inner surface with a shoulder 13 against which may be fixed a casing 14 which will be hereinafter called the inner casing. .4

The lower end of the inner casing 14 connects with the shoe A and rests upon the shoulder` 13 as clearly illust-rated in Figures 2, 3 and 4 of the drawings.

The inner casing 14 may be fastened to the shoe A in any suitable manner or may simply rest thereon.

In connection with the forming o r drilling of wells,

it is usually necessary to drill or outer casing 15 through the ordinary surface clays 16 and then through the cement, sand and gravel formations 17 which are usually found just above the water bearing formations 18.

Th surface clays 16 and through the cement, sand and gravel formations 17 until it rests upon the upper surfaces of the water bearing formations 18.

The cement, sand and gravel formations are of such a nature that the outer casing 15 may be driven through but cannot be easily withdrawn because the formations 17 and 18 frictionally bind the casing 15 and prevent its withdrawal.

e outer casing 15 is driven through the.

Withour method of producing a well the casing 15 simply stops at thelower end of the formation 17 and just above the water bearing formation 18 and it is not necessary to withdraw the outer casing 15.

The strainer 12 is inserted in the water bearing formation 18 below the lower end of the casing 15 in the manner we will now describe in detail. The strainer 12 is mounted upon the shoe A in any suitable manner and inserted within the casing 15 and lowered until it rests upon the water bearing formation 18.

The strainer 12 and shoe A are open ended so that the gravel in and around the lower end of the shoe A may be withdrawn, washed or bailed out through the strainer and shoe, and as the water bearing formation 18 is withdrawn, the shoe and strainer will belowered through the water bearing formation until the lower end of the shoe passes clear through the water bearing formation 18 and rests upon the rock or shale19, at which time the strainer will be completely exposed below the lower end of the casing 15'.

he inner casing 14 may be used for lowering-the shoe and strainer and permits any well-drilling tools to be inserted therethrough for bailing out the water bearing formation'in and around the lower end of the shoe A or washed by hydraulic process or compressed air used to lift'same.

The water bearing formation is usually quite loose and by suction, pumping or bailing out the material in and around the lower end of the shoe A, it is permitted to move downwardly due to the weight of the casing 14,v until it reaches which time the strainer 12 is exposed the required alnount. The casing 14 may then be cut oli' so that only a portion thereof is left within the shoe, as shown in Figure 3 otI the drawings or in case the casing has not been fastenedto the shoe A, then it can be removed by simply lifting it out of the shoe.

It may be here mentioned that the connection between the casing 14 and the shoe rA may be screw threaded with threads of a pitch opposite to the pitch ofthe threads of the above line of tubular sections forming the casing 14 so that by simply rotating the casing 14, it will be lunscrewed from the shoe A.

This screw threaded connection we have not shown in the drawings and of course, it is only an obvious way of accomplishing the result of disconnecting the inner casing from the shoe A.

After lthe strainer has been inserted within the water bearing formation 18, as shown in Figure 3 of the drawings, then some quick setting -cement or lead wool 20 may be dropped into the casing 15 and within the lower end of the shoe A at the lower end of the strainer and shoe so for forming a seal the desired depth at l thatall water passingtherein will have-to travel through the strainer 12.

In Figure 4 of the drawings, I have shown a concrete strainer 21 resting in a V shaped notch 22 formed in the shoe A. This simply illustrates a slight variation in the shape of the shoe to accommodate the concrete strainer.

It will be noted that the outer wall of the strainer is substantially flush with the outer wall of the shoe A. V 's y`\Our method of lowering a strainer in place below t-he lower end of a. casing may be equally as well used in connection with old wells where it' is necessary to remove the old strainer and insert a new one and in such a` case the shoe A and st-rainer,may be used with an inner casing 14 without iii any way tampering with the outer casing.

It may be here mentioned that in many cases it would be impossible to drive the outer casing a short distance and then withdraw it afterthe strainer is in place because the outer casing will become weakened by age It may be said that with our method of insert-ing the strainer you could actually put a new strainer in position which was greater in length than the old strainer 4because you can ,go down and withdraw the water bearing formation below the lower end of the outer casing.

Some changes may be made in the method of producing wells and it is our intention to cover by our claims any method ,.of'producing a. well, wherein it is not/necessary to withdraw the outer casing and where the strainer may be inserted through the outer casing and' lowered below the lower end of the Iouter casing.

We claim as our invention: v

1. The method of producing a well comprising the inserting in the ground of an outer casing until it` reaches the desired depth, the inserting of an inner casini? within the outer casing, the inner. casing iaving a shoe at its lower end, thebot/tom o whichr is open, a strainer carriedby the shoe, the forcing ofthe inner casing below the lower end of the outer casing .until the strainer is exposed below the lower end of the outer casing the withdrawal of a water bearing formation through said shoe and then removing the inner casing leaving the shoe and strainer for forming a continuation 'of the outer casingwhereby water withdrawn through said outer casing will passthrough said strainer.

2. The method of producing a well comprising the Cinserting in the ground of an outer casing until it reaches a water bearing formation, ing within the ogiter casing, a sho'e secured to Nth lower end of the inner casing,- a

the inserting of an inner casstrainer on the shoe and on the outside of ing until Vthe strainer is exposed below the lower end ofthe outer casing and then re- `moving the inner casing leavin the shoe v and strainer and the expanding o the pper l'end of the strainer to engage the inner surface of the outer casing.

3. The method of producing a well comprising the inserting in the ground of an outer casing until it reaches the desired depth, the inserting in the casing of a shoe having a strainer thereon and driving the shoe below the lower end of the casing 'until the strainer is exposed and the shoe and strainer form a continuation of the casing and then sealing the lower end of thev shoe whereby water entering said casing must passthrough said strainer.

4. The method of producing a well comprising the inserting lin the ground of an ing formation, the'inserting in the casing of an open ended shoe having. a strainer thereon and'driving-the shoe into the water bearing formation below the lower end of the casing until the strainer is exposed,

Aouter casing until it reaches a `water bear' the shoe rests on a shale or rock formation and the shoe and strainer form a continua.-

tion, of thed casing, the withdrawal of the water bearing formation as the shoe const rainers are being so driven and the sealing of the open end ofthe shoe after it rests on said shale or rock formation.

5. A strainer shoe comprising a tubular member having its lower edge sharpenedl and a shoulder formed above the lower edge of said member for having a strainer rest thereon, a portion of said member extending up into the strainer, andv a casing secured vto said portion for supporting the shoe and strainer as they are lowered to operative position.

6. prisi-ng the inserting of a ground to a depth where its just above the water bearing formation of the ground,th inserting o a strainer in said casing, an inner casing extending to the bottom 'of said strainer whereby the,

casing in the lower end is strainer is supported and the water bearing formation can be withdrawn fthrough said inner casing but not through the strainer thereby permitting the strainer to pass into The method of producing a well com- Des Moines, Iowa, Decemberf30, 1925.

THOMAS w. 'riionrnzI Groes THORPE.. 

